Known embodiments of loading devices for aircraft for the partially automated loading and unloading of cargo units are integrated directly into the cargo hold or its floor space. Among other things, such loading devices have a plurality of conveying systems, guiding elements and movement aids, and are used for the at least partially automated loading and unloading of cargo holds with standardized cargo units with minimal personnel requirements.
The movement aids are designed as roller paths, ball mats of the like, for example, and reduce friction between the floor space and underside of the cargo units to facilitate a positioning of the cargo units on the floor space of the cargo hold.
On the one hand, the guiding elements are used to reliably guide the cargo units while the conveying systems position them. For example, the guiding elements prevent the cargo units from becoming jammed or wedged against each other or within the cargo space. On the other hand, the guiding elements act to reliably secure the individual cargo units after positioned in the cargo hold against unintended slippage during transport. The cargo units are fixed in place by additional securing elements arranged on the floor space of the cargo hold, e.g., detent pawls, erectable latching elements or the like. The guiding elements are essentially arranged parallel to the longitudinal axis of the aircraft in the cargo hold.
The cargo units have standardized dimensions, and are formed as pallets or containers, for example. The cargo units also have guiding units that are insertable into the guiding elements arranged in the area of the cargo hold. For example, so-called z-guides are laterally arranged on the cargo units, and are insertable into correspondingly designed grooves of the guiding elements arranged in the area of the cargo hold walls. The cargo units can hence be shifted only parallel to the longitudinal axis of the aircraft in the cargo hold in the area of the guiding elements. Movements by the cargo units in the direction transverse to the longitudinal axis of the aircraft are precluded above a tolerance range, thereby securing the cargo units against uncontrolled transverse movements. In addition, the z-guides additionally prevent the cargo units from “lifting” from the floor space of the cargo hold parallel to its vertical axis, which is important during turbulence or rapid descent, for example.
Among other things, the conveying systems of known loading and unloading devices have at least one motor-driven, and preferably anti-slip, transport roller. The anti-slip design of the transport rollers in the conveying systems improves the traction between the underside of the cargo units and/or the transport roller. The undersides of the cargo units rest on at least areas of the transport rollers of the conveying systems, so that the conveying systems can move the cargo units on the floor space in the cargo hold in one direction in space. An abutting cargo unit can here only move in one direction in space perpendicular to the rotational axis of the transport roller. In addition, the cargo units here move essentially parallel to the floor space of the cargo hold. A plurality of conveying systems are preferably spaced uniformly apart relative to each other over the floor spaces of the cargo hold. The (longitudinal) conveying directions for moving the cargo units in the direction of the longitudinal axis of the aircraft are here integrated into the floor space of the cargo hold in such a way that the rotational axes of the transport rollers of these conveying systems are aligned roughly transverse to the longitudinal axis of the aircraft. So that the cargo units can also be moved transverse to the longitudinal direction of the aircraft, additional conveying systems are integrated in the floor space turned by 90°, so that the rotational axes of the transport rollers of these (transverse) conveying systems are essentially aligned parallel to the longitudinal axis of the aircraft. The spatial distance between the conveying systems is here preferably selected in such a way that at least two respective conveying systems are in simultaneous contact with an underside of a cargo unit.
In addition, so-called “scrab” sensors and optical sensors are integrated into the conveying systems.
The optical sensor is used to detect a cargo unit resting in the area of the respective conveying system, so that only those conveying systems having a cargo unit laying thereon are actuated by an open and/or closed loop controllers. This optimizes the power consumption of the entire device. The optical sensor preferably operates without contact with a radiation source and radiation detected based on the principle of a reflective light barrier. The optical sensor can here operate in the entire electromagnetic spectrum.
A so-called “scrab” sensor detects the movement of an applied cargo unit in the respective transport direction of the conveying system in question. The mechanically acting “scrab” sensor essentially encompasses an impeller, which is linked with the transport roller via a sliding clutch. The impeller has a somewhat larger diameter than the diameter of the transport roller in the conveying system to ensure a reliable mechanical contact with an applied cargo unit. Permanent magnets are incorporated into the impeller for acquiring the movements of the impeller. A Hall sensor can be used to determine the rotational velocity of the impeller, and the rotational velocity can be evaluate via an open and/or closed loop controller. The rotational velocity of the impeller is equal to the rotational velocity of the transport roller with the conveying system in an unloaded state. However, if a cargo unit rests on the conveying system, due to the significantly higher frictional value between the impeller of the “scrab” sensor and the underside of the cargo unit the rotational velocity of the impeller, even with a sliding transport roller, is determined essentially based on the actual rate of advance of the cargo unit via the conveying system. As a result, the open and/or closed loop controller can detect and effectively control the movements of the cargo units in the cargo hold. However, a “scrab” sensor can only determine the movement of a cargo unit in the direction in space perpendicular to the rotational axis of the transport roller of the involved conveying system.
Both the conveying systems and the movement aids are essentially integrated in the area of the floor space of the aircraft cargo hold to be loaded, while the guiding elements can also be arranged in the area of the cargo hold walls. The conveying systems and movement aids essentially are flush with the floor space of the cargo hold to form a continuous loading plane.
Due to the essentially purely mechanical operating mechanism, the “scrab” sensors are susceptible to failure and wear. In addition, the known “scrab” sensors can only acquire the speed of movement, acceleration or position of an applied cargo unit in the direction of a respective spatial dimension, e.g., in the direction of the longitudinal or transverse axis of the aircraft. However, the limited space conditions in the cargo holds of modern aircraft often make it necessary to additionally swivel the cargo units around their vertical axis, so that a sensor suitable for acquiring rotational movements must make it possible to simultaneously determine the movement and position of a cargo unit in both the direction of the longitudinal axis of the aircraft and transverse thereto. Further, it has been necessary to date that each conveying system be equipped both with an optical sensor for acquiring an applied cargo unit and an essentially mechanically operating “scrab” sensor, so that at least the direction of movement of a cargo unit can be determined perpendicular to the rotational axis of the transport roller of the conveying system, parallel to the floor space of the cargo hold.